Prevalence and Prognostic Significance of Pulmonary Function Test Abnormalities in Hospitalized Patients With Acute Decompensated Heart Failure With Preserved and Reduced Ejection Fraction

BACKGROUND: This study evaluated the prevalence and prognostic impact of lung function abnormalities in patients with acute decompensated heart failure (ADHF) with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). METHODS AND RESULTS: Of the 1,012 consecutive patients who were admitted to Nara Medical University with ADHF between 2011 and 2018, 657 routinely underwent spirometry (pulmonary function test [PFT]) before discharge. Lung function was classified as normal or abnormal (restrictive, obstructive, or mixed). Abnormal PFTs were seen in 63.0% of patients with ADHF (36.7%, 13.1%, and 13.2% for restrictive, obstructive, and mixed, respectively). The prevalence of abnormal PFT increased with age (P<0.001). Overall, abnormal PFT was an independent predictor of the composite endpoint of cardiovascular mortality or hospitalization for HF (adjusted hazard ratio [HR] 1.402; 95% confidence interval [CI] 1.039-1.914; P=0.027). Abnormal PFT (adjusted HR 2.294; 95% CI 1.368-4.064; P=0.001), as well as the restrictive (HR 2.299; 95% CI 1.322-4.175; P=0.003) and mixed (HR 2.784; 95% CI 1.399-5.581; P=0.004) patterns, were predictive of the composite endpoint in HFpEF, but not in HFrEF. CONCLUSIONS: Abnormal PFT was prevalent and associated with poor outcomes in ADHF. Spirometry may be a useful tool in patients with ADHF, especially in those with HFpEF, to identify those at higher risk of a poorer outcome.